The present invention relates to a web cleaning assembly for use in the fuser section of a electrophotographic copier/printer apparatus and in one of its aspects relates to an assembly for mounting a cleaning web within the fuser section of an electrophotographic apparatus which allows the web to be easily and quickly serviced and/or replaced from outside the fuser section housing by a single service operator.
In a typical electrophotographic machine (e.g. copier, duplicators, printers, etc.), a continuous loop of photoconductor film is commonly used to transfer an image from an input section onto a receiving medium (e.g. a sheet of paper or the like). The film is charged and passed through an input section where an image (i.e. analog or digital) is projected onto the charged film. The film then moves through a developing section where a toner is applied to the charged image and on through an image transfer section where the image is transferred to the sheet of paper. The paper is subsequently passed through a fuser section where the toner is fixed to the paper by passing the paper between two, opposed rollers, i.e. a pressure roller and a fuser roller, one of which is heated. For example, it is common to heat the fuser roller by positioning the fuser roller in contact with one or more heater rollers which, in turn, transfer heat to the fuser roller.
A known problem in fuser sections of this type is that known as xe2x80x9coffsetxe2x80x9d which occurs when some of the heat-softened toner particles remain on the fuser roller and are not transferred to the paper as desired. As well understood in the art, this offset can severely affect the quality of the copies being made by the machine. To alleviate this problem, a release oil is typically applied onto the fuser roller to prevent the toner from sticking thereto.
Due to the direct contact between the fuser roller and the heater rollers, the heater rollers also effectively act as cleaning rollers in that they pick up excess release oil along with other contaminants, e.g. residual toner, paper dust, etc., from the fuser roller. In turn, these contaminants must be continuously removed from the heater rollers during the copying operation in order to maintain high quality copies from the machine. Accordingly, most machines of this type now include some means for continuously xe2x80x9ccleaningxe2x80x9d these contaminants off of the heater rollers during the copying operation.
One known way to clean the heater rollers of this type machine is to position a web cleaning assembly within the fuser section of the machine which includes a cleaning material which, in turn, continuously xe2x80x9cwipesxe2x80x9d the contaminants off of the fuser roller when the machine is in operation. This cleaning material is typically a substantial length of a web of cleaning material (i.e. woven material such as NOMEX) is wound onto a supply roller in the web cleaning assembly. During the copying operation, the web of material contacts the heater rollers as the material is advanced off of the supply roller and onto a take-up roller which, in turn, is also mounted in the cleaning assembly. Since the web material is regularly advanced during the copying operation, the initial supply of web material on the supply roller will ultimately run out and will need to be replaced in order to maintain the quality of the copies being made by the machine. That is, the take-up roller with the used web thereon and the old, now empty supply roller will both need to be removed and replaced with new ones whenever the supply of web material runs out.
Since these rollers will need to be replaced on a relatively frequent basis, the procedure for changing out the rollers should be as easy and as mistake proof as possible. Preferably, this can be simple enough that an operator of the machine, vis-à-vis a dedicated service technician, can be given minimal training to perform this task as needed thereby averting a service call each time the web material runs out thereby significantly reducing the operating costs of the machine.
In known prior-art machines of this type, the supply roller is normally replaced by an experienced technician who pulls the web cleaning assembly out from the fuser section on a slide rail which is mounted within the fuser section housing. Due to the position of the cleaning assembly within the fuser housing during the copying operation, the cleaning assembly, once pulled from the housing, will hang on the slide rail such that the take-up roller is on the low side of the frame of the assembly thereby making it difficult for the technician to access or view the take-up roller without kneeling in an awkward position. A spring-loaded pin is pulled out of one end of the take-up roller which is then lifted off a pin at the other end. Once one roller (e.g. full take-up roller) is free, the other roller (e.g. empty supply roller) must be removed in a similar manner.
Further, such known cleaning assemblies have no provisions for the technician to set one roller down while he removes or works on the other roller thereby requiring the technician to hold the free roller while he is removing/replacing the other roller. This, too, can prove awkward and challenging for a single technician. As will be recognized, this relatively difficult and sophisticated procedure can substantially add to the downtime and maintenance costs of the machine being serviced. Accordingly, the advantages of having ready and easy access to the web cleaning assembly so that the web of cleaning material can easily and quickly be removed and replaced by a single operator should be readily apparent.
The present invention provides an electrophotographic apparatus having a fuser section which includes a web cleaning assembly and a method for servicing the web cleaning assembly to remove and replace the supply and take-up rollers therein. Basically, the web cleaning assembly is pivotably connected to a slide in the housing of the fuser section so that the web cleaning assembly can be slid out of the housing and then rotated to a service position in which the supply and take-up rollers are easily accessible for servicing.
More specifically, the present invention relates to an electrophotographic apparatus having a fuser section which, in turn, includes a web cleaning assembly. The web cleaning assembly includes a supply roller on which a web of cleaning material is wound and a take-up roller which receives the used cleaning material after the material has contacted and removed contaminants from the heater rollers in the fuser section of the apparatus.
The frame of web cleaning assembly has a front and a back which are connected together by a base element. The frame is connected to a telescopic slide in the housing of the fuser section by a pivot connection so that the web cleaning assembly can be slid out of the housing and then rotated from its operable position to a service position. A releasable latch is provided to latch the assembly in the service position. The pivot connection is formed by a pair of slidable pins on the frame which are rotatably received by supports on the slide. These pins can be retracted from the supports on the slide so that the web cleaning assembly can completely removed from the slide when desired.
Both the supply roller and the take-up rollers are releasably mounted in the frame in that a first end of each respective roller is slidably received within a respective first journal box which, in turn, is mounted in the back of the frame. The other or second end of each of each roller is received in its respective second journal box which, in turn, is slidably mounted in the front of the frame so that the second journal boxes can be moved between an operable position where the second ends of the rollers are positioned therein and a retracted position where the second ends of the rollers are free thereof.
From the above, it can be seen that the supply and take-up rollers within the web cleaning assembly can quickly and easily be serviced by sliding the assembly out of the fuser section and then rotating and latching the assembly in a service position. This provides ready access to both of the rollers which can then be quickly removed by retracting the second journal boxes and sliding the rollers out of their respective first journal boxes. New supply and take-up rollers can then be installed by reversing the above-described, removal procedure. The web cleaning assembly is then released from the service position, rotated back to the original or operable position, and then slid back into the fuser section.